1. Technical Field
The present disclosure relates to a backlight assembly, a display device having the backlight assembly, and a method of manufacturing the backlight assembly. More specifically, the present disclosure relates to a backlight assembly capable of efficiently radiating heat generated by a light source, a display device having the backlight assembly, and a method of manufacturing the backlight assembly.
2. Discussion of Related Art
In general, a digital information display (DID) needs high reliability to achieve its intended purpose. Because a liquid crystal display (LCD) device, which is one kind of DID, includes an LCD panel that is vulnerable to high temperature, controlling the temperature of the LCD device is important for the reliability of the LCD device.
Heat from the LCD device is mostly generated by a backlight assembly providing light to the LCD panel. Backlight assemblies that may be used for the LCD device may be divided into a direct downward-type backlight assembly and an edge-type backlight assembly, based on the deposition of a light source. A plurality of light sources is disposed under the display panel in the direct downward-type backlight assembly. The edge-type backlight assembly includes a light source disposed at a side of a light-guiding plate to provide light to the display panel.
One example of the light source that may be used for the backlight assembly is a cold cathode fluorescent lamp (CCFL). Another example is a light-emitting diode (LED) that has favorable characteristics, such as small volume, light weight, low power consumption, and the like.
Because the direct downward-type backlight assembly includes a number of light sources, the heat generated by the light sources needs to be externally radiated. When the heat generated by the light sources is not efficiently radiated, the temperature of the display device is increased, and an LCD panel is damaged, thereby causing problems such as discoloration, degradation of a liquid crystal, bruising of a liquid crystal, and the like. Furthermore, elements employed in the display device, for example, a mold frame, may be deformed or may be discolored, and an efficiency of the light source may be deteriorated.
Thus, a conventional DID device having a display part that is vulnerable to high temperature includes a heat spreader disposed under a light source to radiate heat generated by the light source. The heat spreader is disposed between a reflective sheet and a bottom plate of a receiving container, the reflective sheet reflecting light emitted from the light source, the receiving container receiving the light source. Examples of a conventional heat spreader include a graphite sheet, which has been found to be advantageous in spreading heat. The graphite sheet has a thickness of about 1 mm, and is disposed between the reflective sheet and the bottom plate of the receiving container.
The graphite sheet is manufactured, however, by compressing graphite powder at a high temperature under a high pressure. Thus, the graphite sheet is easily broken. Therefore, graphite powder may escape from a broken graphite sheet, and the graphite powder may serve as an unwanted impurity in a backlight assembly.
Furthermore, the graphite sheet barely makes complete contact with a bottom plate of a receiving container. Thus, an air layer may be formed between the graphite sheet and the bottom plate. This air layer hinders the graphite sheet from radiating heat.
Even if an impurity-blocking layer is formed on an upper surface of the graphite sheet, graphite powder may not be prevented from moving toward the liquid crystal display panel in view of the structure of a backlight assembly.
Furthermore, when a backlight assembly includes the impurity-blocking layer, an adhesive tape is required in order to couple the impurity-blocking layer to the reflective sheet. Thus, processes and costs for manufacturing the backlight assembly are increased.
Also, when a graphite sheet is once more adhered to a bottom plate of a receiving container after the graphite sheet has been removed from the bottom plate, graphite powder may be adhered to the bottom plate. Thus, both the receiving container and the graphite sheet may become unusable.